Interface regulation enabling three-dimensional Li1.3Al0.3Ti1.7(PO4)3-reinforced composite solid electrolyte for high-performance lithium batteries

Composite solid electrolyte (CSE) consisting of Li + conductive fillers and polymer matrix has become attractive for high energy-density lithium batteries . Current researches focus on the “ceramic in polymer”-type CSE due to the severe agglomeration of ceramic particles. Consequently, the destroyed percolation network impedes the further improvement in ionic conductivity . In this work, we report a novel structural design of ceramic-enriched CSE consisting of three-dimensional (3D) interconnected Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 (LATP), polyvinylidene fluoride (PVDF) and LiN(SO 2 ) 2 (CF 3 ) 2 (LiTFSI). The 3D LATP network is constructed through the surface functionalization of LATP particles by polymethyl methacrylate (PMMA). Owing to the intermolecular interaction between PMMA and PVDF, the incorporation of PMMA-coated LATP (denoted as LATP@PMMA) enables the uniform distribution of ceramic phase and generates interconnected LATP network. Noticeably, such an electrolyte maximizes the utilization of inorganic fillers through the facile treatment of zero-dimensional materials, which is comparable to those 3D template-derived fillers. Furthermore, continuous Li + conduction pathways through LATP framework and LATP/PVDF interphase are guaranteed by the enhanced affinity of LATP towards PVDF matrix and the intrinsic Li +  complexation capability of PMMA. Remarkable cycling performances of the LiNi 0.5 Co 0.2 Mn 0.3 O 2 /LATP@PMMA-PVDF/Li batteries confirm the feasibility of 3D ceramic-enriched composite electrolyte in the application of solid-state lithium batteries.